Lamp socket with clamp member attached to body



Sept. 14,1965 H.w. SCHICK ETAL 1 LAMP SOCKET WITH CLAMP MEMBER ATTACHED TO BODY Original Filed July 24, 1962 FIG. I

mi uwil I NVENTORS JOHN W. PETERSON HENRY w. SCHICK ATTORNEYS United States Patent 3,296,711 LAMP SUCKET WITH CLAMP MEMBER ATTACHED TO BODY Henry W. Schick, Mastic Beach, and John W. Peterson, Douglaston, N.Y., assignors to Gilbert Manufacturing Company, Ind, Long Island City, N.Y., a corporation of New York Original application July 24-, 1962, Ser. No. 212,085, now Patent No. 3,151,926, dated Oct. 6, 1964. Divided and this application Aug. 20, 1964, Ser. No. 395,352 7 Claims. (Cl. 33999) This application is a division of our copending application Serial No. 212,085, filed July 24, 1962, and entitled Lamp Socket, now United States Letters Patent No. 3,151,926, issued on October 6, 1964, and assigned to the same assignee.

This invention relates to lamp sockets which are adapted to be mounted along the length of an electrical conductor cord at any point thereof and more particularly to lamp socket assembly of the pin-tap type in which connection is made between the electrical contact elements of the socket and the conductor cord by piercing the Wires of the conductor cord.

The present invention is directed to a relatively simple lamp socket which may be removably secured to and mounted at any point along a conductor cord which supplies the current for the lamp bulb in the socket. In accordance with the invention, the lamp socket comprises a shell or husk of plastic material having internal threads to receive and hold the base of the lamp bulb. Two grooves are formed on opposite walls of the shell for receiving and holding respective blade-type electric contact members. One end of each contact member is formed with a prong for piercing through the insulation of the conductor cord to make electrical contact with a conductor wire and each contact member is also formed with a tab or tongue to make contact with one of the electrical contact points on the lamp bulb base. In this way a current path is provided from the conductor cord to the bulb. The bottom of the socket shell is formed with a channel to hold the conductor cord and a wedge piece is provided to be placed in the channel on top of the conductor cord to hold it within the channel. In order to secure the wedge piece to the shell and to force the prongs of the contact members to pierce through the conductor wires, an L-shaped clamp is provided. One end of the clamp preferably hooks over the top of the shell and the other end fits over the bottom of the wedge piece and is fastened onto the bottom of the shell. The clamp is made of suitable size and of a suitable material so that a tight fit is achieved and enough pressure is applied to the wedge piece to force it into the channel thereby causing the prongs to pierce the conductor wire. The clamp is also formed with a clip which allows the complete socket assembly and bulb to be mounted at a desired location, for example, on the branch of a Christmas tree.

The above described socket has several advantages. First of all, it is relatively simple in construction and assembly and needs no soldering or other type fastening arrangement to make contact between the socket contact members and the wires of the conductor cord. Further, the pin-tap assembly of the electrical contact blades makes the socket attachable at any point along the conductor cord; also, the L-shaped clamp is preferably made of tempered spring steel and its relatively simple shape uses a minimum amount of material and provides for easy manufacture and assembly. The use of spring steel for the clamp also gives the clip formed thereon better holding properties and increased life.

In a preferred form of the invention, the wedge piece is of pyramidal shape so that when it is laid in the chanice nel against the wires the wires follow the contour of the wedge piece and strain relief is provided by virture of the conductor wires running over the highest portion of the pyramid. This is a relatively simple way of providing strain relief without the use of any additional parts.

It is therefore, an object of this invention to provide a lamp socket of the pin-tap type wherein the clamp which secures the conductor holding piece is L-shaped and is provided with a clip to secure the socket assembly to a support.

A further object of the invention is to provide a lamp socket having blade type contact members which pierce through the insulation of a conductor cord, the conductor cord being held in a channel in the socket and pressed into electrical contact with the contact members by a conductor holding wedge piece.

Yet another object of the invention is to provide a lamp socket of the pin-tap type in which the conductor cord is held in a channel in the socket and pressed into electrical contact with the prong of blade contact members by a wedge piece which is held within the channel by an L-shaped clamp member.

Still another object of the invention is to provide a lamp socket in which the wedge piece holding the wires within the socket is shaped to provide strain relief.

Other objects and advantages of the present invention will become more apparent upon reference to the following specification and annexed drawings in which:

FIGURE 1 is a side elevational view of the lamp socket assembly, with the lamp socket shown partially broken away in order to illustrate certain features of the invention;

FIGURE 2 is a front elevational view of the lamp socket taken partially in section along lines 2-2, FIG- URE 1 and partially broken away;

FIGURE 3 is a perspective view of the bottom of the lamp socket showing a portion of the conductor cord running therethrough;

FIGURE 4 is a perspective view of the wedge piece;

FIGURE 5 is a front elevational view of one of the blade contact members;

FIGURE 6 is a perspective view of the bottom of the clamp of the lamp socket of FIGURES 1-3;; and

FIGURE 7 is a front elevational view partly broken away of another embodiment of the invention.

Referring to FIGURES 1-6, the lamp socket is formed by a substantially hollow shell or husk 10, which has an opening 11 at the top thereof, end walls 12 and 13, and side walls 14 and 15. The top opening 11 communicates with a cavity 16 which extends substantially the entire height of the shell. The shell 10, as well as the other non-metallic parts of the socket, is preferably made of a plastic insulating material such as Bakelite or of another plastic material which has the necessary strength. The top opening 11 of the shell is flared out to accommodate the base 18 and the bottom portion of the glass envelope of a bulb 17 which is screwed into threads 19 formed on the side walls 14 and 15. The bulb 16 may be of any desired shape, type, and/or Wattage and the size of the shell 10 and threads 19 may be varied to accept different bulbs.

The end walls 12 and 13 of the shell are respectively formed with channels or grooves 21 (only one of which is shown in FIGURE 2.) to hold a respective blade contact member 23 or 24. The grooves 21 are made of a suitable size so that the blade contact members 23 and 24 are tightly held therein when they are placed in the grooves. As shown in FIGURE 5 each blade contact member is formed with a downwardly extending sharp pointed prong 25 at the bottom end thereof which is of a size to make contact with one of the wires 26 or 27 of a two conductor cord 28. The blade contact members 23 and 24 are formed and located within the shell so that the prong of one is adjacent the side wall 14 and the prong of the other adjacent the side wall 15. Therefore, each prong will make contact with only one of the wires 26 or 27. Any suitably shaped blade contact member may be utilized so long as it has the sharp pointed prong to pierce the current carrying wire and can be held within the socket body.

Blade contact member 23 has a tongue which extends into the shell cavity 16 to make electrical contact with the bottom contact point 31 of the lamp bulb base 18 when the bulb is screwed substantially all the way down on the threads 19. The other blade contact member 24 has a bent-out tab portion 32 which makes electrical contact with the metallic threaded portion 33 on the side of the bulb base. In this manner an electric circuit is established to provide current to the lamp filament through the two wires 26 and 27 of the conductor, blade contact members 23 and 24 and their respective tongue and tab 30 and 32, and the two contact points 31 and 33 on the lamp bulb base.

The socket shell 10 also has a bottom wall 36 which is formed with a longitudinal channel 37 therein running between the end walls 12 and 13. The channel 37 does not take up all of the bottom wall 36 so that ledge pieces 38 are left on either side of the channel within the cavity at the bottom wall of the shell. The channel 37 extends part way up into the end walls 12 and 13 which have cut out sections 39 (FIGURE 1) so that the conductor cord 28 may be readily placed in the channel 37 and held Within the socket. The prong 25 of each blade contact member 23 and 24 extends part way down into the channel 37 to a point opposite the openings 39 in end walls 12 and 13 and above the bottom wall 36 of the shell. As described previously, the blade contact members are located in grooves 21 in the end walls. Ledges 38 are left on each side of the channel 37 opening in the bottom wall 36 of the shell.

A wedge piece 40 is provided to fit within the channel 37 and to hold the conductor cord within the shell. The wedge piece holds the conductor cord 28 within the channel 37 and when it is clamped, exerts pressure on the wires 26 and 27 so that the prongs 25 of the blade contact members pierce through the wires. Wedge piece 40 is preferably generally pyramidal in shape with a high point 41 at the center thereof and sloping surfaces 42 tapering off from the high point along the longer dimension of the piece. The center portion of the wedge piece is also cut out on both sides and has sloping surfaces 44 which run from the top of the piece. The surfaces 44 extend down to the bottom of the wedge piece but do not reach the sides 45 thereof so that openings or notches 43, which are shown in FIGURE 4 but not in FIGURE 3, are provided on the piece. Each end of the piece 49 is also provided with two notches 46 which allow the piece 40 to fit over the abutting pieces 47 of the end walls 12 and 13. It can be seen that the piece 40 is symmetrical so that it can be placed either way in the channel 37 with the high point 41 facing in toward the center of cavity 16. Of course, any suitable form of wedge piece may be used and the sloping surfaces are desirable for strain relief but not altogether necessary to provide suitable pressure for the Wires against the contact members.

A clamp 50 is used to hold the wedge piece 40 to the socket and to exert pressure on the piece so that the prongs 25 of the blade contacts will pierce through the wires of the conductor cord. The clamp St is formed of tempered spring steel or some other suitable material and is generally L-shaped with a long arm 51, a hook portion 52 at the end thereof and a short arm 53 at the other end of the L. The hook 52 fits over the top edge of the flared opening 11 of the socket while the center portion of the longer arm of the L-shaped clamp is punched out and bent to form a clip 54 which is used to mount the socket and bulb on a desired support.

As shown best in FIGURE 6, the bottom 36 of one (or both) of the side walls is formed with two slots 76. The short arm 53 of clamp 50 is provided with two legs 78 which are preferably barbed and are of slightly smaller size than the slots 76.

In assembling the complete lamp socket, the conductor cord 28 is first laid into the channel 37 into which the prongs 25 extend near the end walls 12 and 13. The wedge piece 461 is next placed on the shorter arm 53 of the L-shaped clamp and the legs 78 are driven home into the slots 76. The wedge piece is next forced into position so that its bottom is substantially flush with the bottom 36 of the socket by applying pressure to the piece and forcing the hook 523 of the clamp over the top edge of the shell. Of course, the reverse procedure may be used and the hook 52 fastened first. Since the L-shaped clamp is made of spring steel, the wedge piece 46 is forced into the channel and sufficient pressure is exerted to force wires 26 and 27 up onto the prongs 25. The prongs pierce through the insulation surrounding the wires 26 and 27 so that the blade contact-s make electrical contact with the inner conductors of the wires.

It should be noted that both of the wires in the channel are forced to follow the general contour of the wedgeshaped piece 49 in the channel so that at the center of the channel the wires run over the high point 41. The sloping surfaces 42 and the high point 41 of the wedge piece provide strain relief for the wires and prevent them from being separated from the blade contact members when a pull is exerted on the wires.

FIGURE 7 shows another embodiment of the invention in which the wedge piece 40 is again held in the channel by the L-shaped clamp 50. In this case, the side wall 14 or 15 of the socket shell, or both, is provided with a notched opening 57 and the bottom end of the clamp has a hook 58 which fits within opening 57 and holds this end of the clamp to the side wall. As before, the clamp 5t) holds the wedge piece 40 within the channel but the clamp extends completely around the bottom 36 of the shell.

In both the embodiments of FIGURES l6 and 7, the short arm 53 does not extend into the channel 37. Therefore, the notches 43 on the wedge piece may be dispensed with.

It should be recognized that the lamp socket of the present invention is of simplified construction which is both economical to produce and easy to assemble. Since the clamp 50 is L-shaped, a minimum amount of material is used for performing the clamping function and also to provide a spring clip 54 to hold the socket and lamp assembly to any desired support. Further, since the clamp member is preferably formed of spring steel material, the clip 54 is stronger than that provided by normal sheetmetal clamps and will last a lot longer.

While preferred embodiments of the invention have been described above, it will be understood that these are illustrative only, and the invention is limited solely by the appended claims.

What is claimed is:

1. A lamp socket assembly comprising a substantially hollow shell having a bottom wall and an opening in the top thereof to receive a lamp bulb, a pair of blade type contact members each having a prong portion at the bottom thereof, said shell having means to receive and hold the blade contact members, a channel in the bottom of said shell through a portion of said bottom wall adapted to receive a pair of current carrying wires, a wedge piece to fit in said channel and adapted to hold the wires therein and press a. wire against the prong of a respective blade member, a slot formed in one of the walls of the shell, and an L-shaped clamp for holding said wedge piece in said channel, said clamp formed with means at one end thereof to fasten the shell at the top opening thereof and.

at the other end with a first portion to engage said wedge piece and a second portion having a barbed leg to extend into said slot to fasten the said other end of the clamp to the shell.

2. A lamp socket assembly comprising a substantially hollow shell having a bottom wall and an opening in the top thereof adapted to receive a lamp bulb, a pair of blade type contact members each having a prong portion at the bottom thereof, said shell having means to receive and hold the blade contact members, a channel in the bottom of said shell adapted to receive a pair of current carrying wires, an opening in the side of said sell, a wedge piece to fit in said channel and adapted to hold the wires therein and press a wire against the prong of a respective blade member, and an L-shaped clamp for holding said wedge piece in said channel, said clam-p formed to engage said wedge piece and to press it into said channel, and also being formed with means at one end thereof to fasten to the shell at the top opening thereof and at the other end to fasten into the opening in the side of the shell.

3. A lamp socket assembly comprising a substantially hollow shell having a bottom wall and an opening in the top thereof to receive a lamp bulb, a pair of blade type contact members each having a prong portion at the bottom thereof, said shell having means to receive and hold the blade contact members, a channel in the bottom of said shell through a portion of said bottom wall adapted to receive a pair of current carrying wires, a wedge piece to fit in said channel and adapted to hold the wires therein and press a wire against the prong of a respective blade member, said wedge piece formed with oppositely sloping surfaces thereon within the channel to provide strain relief for said wires, a slot formed in one of the walls of the shell, and an L-shaped clamp for holding said wedge piece in said channel, said clamp formed with means at one end thereof to fasten to the shell at the top opening thereof and at the other end with a first portion to engage said wedge piece and a second portion having a barbed leg to extend into said slot to fasten the said other end of the clamp to the wall.

4. A lamp socket assembly comprising a substantially hollow shell having a bottom wall and an opening in the top thereof adapted to receive a lamp bulb, a pair of blade type contact members each having a prong portion at the bottom thereof, said shell having means to receive and hold the blade contact members, a channel in the bottom of said shell adapted to receive a pair of current carrying wires, an opening in the side of said shell, a

wedge piece to fit in said channel and adapted to hold the wires therein and press a wire against the prong of a respective blade member, said wedge piece formed with oppositely sloping surfaces thereon within the channel over which said wires run and providing strain relief therefor, and an L-shaped clamp for holding said wedge piece in said channel, said clam-p formed with means at one end thereof to fasten to the shell at the top opening thereof and at the other end to fasten into the opening in the side of the shell after engaging said wedge piece and pressing it into said channel.

5. A lamp socket assembly comprising:

a substantially hollow shell member having a bottom wall and an opening in the top thereof adapted to receive a lamp bulb, the bottom of said shell formed with a channel adapted to receive a pair of current carrying wires,

a pair of contact members each having a portion thereon adapted to make electrical contact with a respective current carrying wire, said shell member having means to hold said contact members,

a wedge piece to fit in said channel and adapted to hold the wires therein,

an aperture in the body of said shell spaced from said channel,

and an L-shaped clamp for holding said wedge piece in said channel, one arm of said clamp formed to engage said wedge piece and press it into said channel and also formed with means extending into the body aperture, to engage said shell and hold the said one arm thereto, the other arm of said clamp formed with means for engaging the shell at said opening in the top thereof.

6. A lamp socket assembly as set forth in claim 5 wherein the aperture in the body of the shell is on the side wall thereof, and said means on said one arm of said clamp member extends into the aperture and engages said side wall.

7. A lamp socket assembly as set forth in claim 5 wherein the aperture in the body of the shell is in the bottom wall thereof and the said one arm of said clamp member is provided with barbs to fasten the said one arm in the said aperture.

No references cited.

JOSEPH Primary Examiner, 

5. A LAMP SOCKET ASSEMBLY COMPRISING: A SUBSTANTIALLY HOLLOW SHELL MEMBER HAVING A BOTTOM WALL AND AN OPENING IN THE TOP THEREOF ADAPTED TO RECEIVE A LAMP BULB, THE BOTTOM OF SAID SHELL FORMED WITH A CHANNEL ADAPTED TO RECEIVE A PAIR OF CURRENT CARRYING WIRES, A PAIR OF CONTACT MEMBERS EACH HAVING A PORTION THEREON ADAPTED TO MAKE ELECTRICAL CONTACT WITH A RESPECTIVE CURRENT CARRYING WIRE, SAID SHELL MEMBER HAVING MEANS TO HOLD SAID CONTACT MEMBERS, A WEDGE PIECE TO FIT IN SAID CHANNEL AND ADAPTED TO HOLD THE WIRES THERIN, AN APERTURE IN THE BODY OF SAID SHELL SPACED FROM SAID CHANNEL, AND AN L-SHAPED CLAMP FOR HOLDING SAID WEDGE PIECE IN SAID CHANNEL, ONE ARM OF SAID CLAMP FORMED TO ENGAGE SAID WEDGE PIECE AND PRESS IT INTO SAID CHANNEL AND ALSO FORMED WITH MEANS EXTENDING INTO THE BODY APERTURE, TO ENGAGE SAID SHELL AND HOLD THE SAID ONE ARM THERETO, THE OTHER ARM OF SAID CLAMP FORMED WITH MEANS FOR ENGAGING THE SHELL AT SAID OPENING IN THE TOP THEREOF. 